1. Field of the Invention
The present invention relates to a method for manufacturing a radiator which is used for heat radiation from a CPU or the like in a computer.
2. Description of Related Art
Heretofore, a manufacturing method of a radiator used for heat radiation from a CPU or the like in a computer has been disclosed in, for example, Japanese Patent Publication Laid-open No. 313080/1998.
This conventional example is a manufacturing method of a radiator wherein a corrugate fin made by bending a metallic thin plate of aluminum or the like into a corrugated shape is bonded onto a base plate by soldering.
Furthermore, Japanese Patent Publication Laid-open No. 204968/1999 discloses a method wherein a fin made by extrusion molding is applied onto a base plate by friction soldering or supersonic soldering to form solder plating, and the solder-plated base plate and fin are bonded together by friction soldering.
However, the above-mentioned conventional example of Japanese Patent Publication Laid-open No. 313080/1998 has a problem wherein the bonded corrugate fin is apt to be thermally deformed because it is bonded by soldering in a high temperature state.
Moreover, the above-mentioned conventional example of Japanese Patent Publication Laid-open No. 204968/1999 has a problem wherein the manufacturing cost is high because the base plate has a structure in which an Ag layer is interposed between a Cu material and an Al material, and the final step is a step of bonding the solder-plated base plate and fin together by friction soldering.
Accordingly, it is an object of the present invention to provide a manufacturing method of a radiator wherein a corrugate fin can inexpensively be bonded to a base plate, and the thermal deformation of the corrugate fin can be prevented by soldering at a low temperature.
The present invention is directed to a manufacturing method of a radiator comprising the steps of:
(1) manually or mechanically fitting a frame onto a corrugate fin made of Al or an Al alloy and bent into a corrugated shape;
(2) manually or mechanically grasping said frame, moving it into a heated recess of a movable solder bath filled with a molten first solder alloy, horizontally moving said movable solder bath while the lower ends of said corrugate fin are dipped in said molten first solder alloy and the lower ends are in a friction state with the bottom surface of said recess, and then applying the first plating of said molten first solder alloy onto the lower ends of said corrugate fin;
(3) heating and melting second solder alloy on a base plate made of one of Cu, a Cu alloy, Al and an Al alloy, rubbing said base plate with a metallic brush which is manually or mechanically moved in a horizontal direction, and then applying the second plating of said molten second solder thereunto; and
(4) manually or mechanically grasping said frame, putting said corrugate fin on said base plate, pressing and heating it on said base plate to thereby melt said first plating and said second plating and to bond said corrugate fin onto said base plate, and then removing said frame from said corrugate fin.
Step (2) can be replaced with
a step (2a) of manually or mechanically grasping said frame, moving it into a heated recess of a movable solder bath filled with a molten first solder alloy, horizontally moving said frame while the lower ends of said corrugate fin are dipped in said molten first solder alloy and the lower ends are in a friction state with the bottom surface of said recess, and then applying the first plating of said molten first solder alloy onto the lower ends of said corrugate fin.
Step (3) can be replaced with
a step (3a) of heating and melting said second solder alloy on a base plate made of one of Cu, a Cu alloy, Al and an Al alloy, bringing a metallic brush into contact therewith, manually or mechanically moving said base plate in a horizontal direction to rub said base plate with said metallic brush, and then applying the second plating of said molten second solder alloy thereunto.
Both steps (2a) and (3a) can be performed in combination.:
Step (2) can also be replaced with
a step (2b) of applying a flux to the lower ends of said corrugate fin fitted in said frame, heating it, and then applying the first plating of said first solder alloy onto the lower ends of said corrugate fin.
Step (3) can also be replaced with
a step (3b) of applying a flux onto a base plate made of one of Cu, a Cu alloy, Al and an Al alloy, heating it, and then applying the second plating of a second solder alloy onto said base plate.
Both steps (2b) and (3b) can be performed together.
Step (2) can also be replaced with
a step (2c) of manually or mechanically grasping said frame, and then, while dipping the lower ends of said corrugate fin in a third solder alloy which is molten, caused to flow, and subjected to ultrasonic vibration, applying the third plating of the molten third solder alloy onto the lower ends of said corrugate fin; and,
Step (3) can also be replaced with
a step (3c) of, while dipping a base plate made of one of Cu, a Cu alloy, Al and an Al alloy in a fourth solder alloy which is molten, caused to flow, and subjected to ultrasonic vibration, applying the fourth plating of a fourth solder alloy onto said base plate.
In the present invention step (3), (3a), (3b) or (3c) can be a precedent step to or a simultaneous step with said step (1),(2),(2a),(2b) or (2c).
In the present invention the entire body can be plated with one of Al, Ni, Cr, Ag and Au, or an alloy of them, after step (4).
In the present invention only a peripheral portion on said base plate can be covered with a metal mask in said step (3), (3a), (3b) or (3c), and said metal mask can be removed from said base plate in said step (4).
In the present invention said first to fourth solder alloys can be made of Sn and Zn, or Zn and Al.
In the present invention said frame can be made of a metal, a ceramic material or a heat-resistant synthetic resin.